Henry c



(No Model.)

11.0. SERGEANT. GOMPRESSOR FOR AIR, m.

Patented pr. 26, 1898.

w [ill ain 1m: Nonms earns :20. pumcvumo. WASHINGTON. cv c..

f ul Improvement in Compressors for Air and UNITED STATES PATENT tries.

HENRY C. SERGEANT, OF 'WESTFIELD, NEW JERSEY, ASSIGNOR TO THE lNGERSOLL-SERGEANT DRILL COMPANY, OF NEW YORK, N. Y.

SPECIFICATION forming part of Letters Patent No. 602,877, dated April 26, 1898.

Application filed June 4, 1897. Serial No. 639,417. (No model.)

To aZZ 101 2-07171 it may concern:

Be it known that I, HENRY C. SERGEANT, of Westfield, in the county of Union and State of New Jersey, have invented a new and useother Gaseous and Aeriform Bodies, of which the following is a specification.

This invention relates to what are known as compound compressors, in which air compressed in one cylinder is transferred to a second cylinder, in which it is further compressed. The object of the invention is to simplify the construction of such compressors.

I will first describe the construction and operation of a compressor embodying myinvention with reference to the accompanying drawings and afterward point out its novelty in claims.

Figure 1 represents a longitudinal elevation, partly in section, of a compressor embodying my invention,which will be described as an air-compressor. Fig. 2 represents an axial section of the low-pressure piston and a side view of the hi gh-pressure piston and its rod and a valve attached thereto for controlling the passage of air through the low-pressure piston, representing the parts in positions difiering from those shown in Fig. 1. Fig. 3 is a view of the parts shown in Fig. 2 as viewed from the right of that figure.

Similar letters of reference designate corresponding parts in all the figures.

A and B designate the two cylinders of unequal caliber, constituting, respectively, the high and low pressure cylinders, arranged end to end in line with each other and fitted, respectively, with pistons A and B. These cylinders are open to each other at their adjacent ends.

The smaller or high-pressure piston B is attached fixedly to the rod 0, which also carries the larger or low-pressure piston A, and it is represented as a simple prolongation of the said rod in the form of a plunger and having around its end a packing a of any suitable kind fitting the cylinder B. The piston A is fitted loosely to the exterior of the rod or piston B, so that the latter may have a limited movement lengthwise independently of the former, as and for the purpose to be presently described.

The outer end of the cylinderA is fitted with a head A in which is a stuffing-box Z2, through which passes the rod (J, to which'motion may be imparted by any suitable meansas, for example, by a crank c on a shaft cl, driven by any suitable motor. The outer end of the cylinder B is fitted with a head B which constitutes a box for two valves e f, which will be presently described.

Close to its head A the cylinder A is furnished with an outwardly-opening valve g of any suitable kind, which opens and closes communication through a pipe h or any suitable conduit between the outer ends of the cylinder A and the cylinder B. At the inner end of the said cylinder A, adjacent to the cylinder B, is the inlet-pipe 2', through which the air to be com pressed enters the compressor.

From the cylinder-head or valve-box B the delivery-pipej for the finally-compressed air may lead to any receiver or to a second compressor of the same or anyothersuitable kind to be further compressed. The valve 6, hereinbefore referred to, in said head or box B is arranged between the pipe h and the cylinder B and opens toward said cylinder. The valve fihereinbefore referred to, opens from the cylinder B toward the delivery-pipe The cylinders A B are represented as in a tank E, through which a constant circulation of cold water is kept up; but any provision may be made for the circulation of water around them for the purpose of keeping them cool.

It has been hereinbefore mentioned that the low-pressure piston A is so fitted to the rod or plunger B, which constitutes the highpressure piston, that the latter may have an independent movement. The said piston A is represented as so fitted on the plunger itself. The object of this independent movement is the opening and closing of communication through the piston A between the portion of the low-pressure cylinder on one side of the said piston and the portion on the other side. This opening and closing is effected by a valve D, which is affixed to the piston B and rod 0 and is represented as a solid collar formed upon and integral with said piston and rod, the'said valve closing against an annular seat Z, formed around a central opening Z in that side of the piston A which is toward the outer end of the cylinder A. From this I seat'passagesmlm are provided through the said piston A toward the other end of said Opposite the valve-seat Z there is provided within the said piston a shouldern,

cylinder.

which serves as a stop to the back of the valve to properly limit its movement Within the piston A. The piston A may be otherwise constructed andpacked in any known or suitable manner not necessary to be here described. The valves 6 f g may be of any suitable kind and provided,as represented, with closing springs;

The operation is as follows: Motion being given to the rod 0 and the piston 13, the valve ,D, moving with them and Working between itsseat Z and the shoulder Z, serves as a driver to communicate motion to the piston A but that piston, being restrained by its friction in the cylinder A, remains stationary at the coinniencement of the stroke of the piston B in either direction, while the valve moves from its seat to the stop it, or vice versa, and so opensor closes the passages m through the piston A. to commence its movement to the right, as indieated by the arrowin Fig. 1.. The valve D,

I the valve arrives at the stop it, when the valve carries the piston A along with B.

enters the cylinder by the pipe i and flows freely through the passages m of the piston A, filling the cylinder, but no compression;

which was closed during the stroke in the opposite direction, immediately'opens, the pis-,

ton A remaining stationary until the back of I will first suppose the piston 13' Airnow I described, While the cylinder A again fillswith air, the air which had been previously comthe drawings. l l

Vhat I claim as my invention is 1. In a compressor the combination with two compression-cylinders and correspondingpia pressed therein and forced into B is further compressed in the latter, closing the valve e and opening the valve f'and passing tothe delivery-pipe, all as illustrated in Fig. l of tons of unequal caliber arranged in line, of a I valve affixed to thesmaller piston for opening and closing passages through thelarger one by a limited movement of thesmaller one relatively to the larger one, substantially as herein described. I

2. In a compound compressor the combination with two compression-cylinders oflunequal caliber arranged in line with each other, of two pistons on one rod fitted to said cylinders respectively, the piston of smallercaliber beingaffixed to the said rod, and the piston of larger caliber having passages through it and containing a valve-seat and being so attached to the smaller piston as to permit an independent movement of the one relatively to the other, a valve affixed to said rod and smaller piston and adapted to said valve-seat for opening and closingthe passages through the larger piston by the movement ofvthe smaller one, substantially as herein described. 3.- The combination Withthe low-pressure piston having passages through it and containing a valve-seat and a stop facing said seat,of the high-pressure piston passing freely through said low-pressure piston and having affixed to it a valve located between said seat and stop and serving to open and close said passages and also to transmit motion from the high-pressure piston in opposite directions to the low-pressure piston, substantially as herein described. l

HENRY C. SERGEANT.

WVitnesses:

FREDK. HAYNES, LIDA M. EGBERT. 

